965  
FNUS74 KHUN 091154  
FWSHUN  
 
SPOT FORECAST FOR GRINDSTONE...USFS  
NATIONAL WEATHER SERVICE HUNTSVILLE AL  
654 AM CDT TUE MAY 9 2017  
 
FORECAST IS BASED ON IGNITION TIME OF 1000 CDT ON MAY 09.  
IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER  
SERVICE.  
   
DISCUSSION
 
 
WESTERLY WINDS BETWEEN 5 AND 10 MPH WITH GUSTS TO AROUND 15 MPH ARE  
EXPECTED THIS AFTERNOON. OTHERWISE, JUST A FEW CLOUDS EXPECTED TODAY  
WITH RELATIVE HUMIDITY VALUES DROPPING TO BETWEEN 35 AND 40 PERCENT  
THIS AFTERNOON. DISPERSION CONDITIONS WILL BE GOOD TODAY WITH MIXING  
HEIGHTS AROUND 5000 FEET OR HIGHER. TRANSPORT WINDS WILL BE HIGHER  
TODAY THAN ON WEDNESDAY, SO FIRE SPREAD POTENTIAL IS A BIT STRONGER  
TODAY. SURFACE WINDS ARE EXPECTED TO BECOME LIGHT AFTER MIDNIGHT AND  
SOME PATCHY FOG IS POSSIBLE TOWARDS DAYBREAK.  
 
WINDS ARE EXPECTED TO BECOME SOUTHWESTERLY ON WEDNESDAY MORNING AND  
A BIT LIGHTER, BUT STILL SHOULD BE BETWEEN 5 AND 10 MPH. RELATIVE  
HUMIDITY VALUES SHOULD REMAIN BETWEEN 35 AND 40 PERCENT. MIXING HEIGHTS  
SHOULD BECOME LOWER BETWEEN 3000 AND 5000 FEET. DISPERSION VALUES  
SHOULD LOWER, BUT STILL REMAIN GOOD. TRANSPORT WINDS WILL BE LIGHTER,  
WHICH WILL LESSEN FIRE SPREAD POTENTIAL A BIT.  
 
   
REST OF TODAY
 
 
SKY/WEATHER.........SUNNY (10-20 PERCENT).  
MAX TEMPERATURE.....AROUND 85-87.  
MIN HUMIDITY........35-40 PERCENT.  
WIND (20 FT)........WEST WINDS 5 TO 10 MPH.  
CWR.................0 PERCENT.  
CHANCE OF PCPN......0 PERCENT.  
MIXING HEIGHT.......2600-3700 FT AGL...INCREASING TO 4800-6000 FT  
AGL IN THE AFTERNOON.  
TRANSPORT WINDS.....WEST 13 TO 15 MPH.  
LVORI...............1.  
 
TIME (CDT) 10A 11A 12P 1PM 2PM 3PM 4PM 5PM  
SKY (%).........MCR MCR MCR MCR MCR MCR MCR MCR  
WEATHER COV.....  
WEATHER TYPE....  
TEMP............76 80 82 84 85 86 86 85  
RH..............48 44 41 38 36 36 36 39  
20 FT WIND DIR..250 250 260 260 260 260 250 250  
20 FT WIND SPD..5 5 6 6 7 7 7 6  
20 FT WIND GUST.10 10 10 10 15 15 15 15  
MIX HGT (KFT)...2.6 3.7 4.8 5.6 6.0 6.0 5.7 5.6  
TRANSP WIND DIR.260 260 260 260 250 250 250 250  
TRANSP WIND SPD.13 14 13 13 13 14 14 15  
DISPERSION IDX..6 62 71 80 84 92 89 95  
LVORI...........1 1 1 1 1 1 1 1  
CWR.............0 0 0 0 0 0 0 0  
CHC OF PCPN (%).0 0 0 0 0 0 0 0  
   
TONIGHT
 
 
SKY/WEATHER.........CLEAR (0-10 PERCENT).  
MIN TEMPERATURE.....AROUND 58-60.  
MAX HUMIDITY........100 PERCENT.  
WIND (20 FT)........SOUTHWEST WINDS AROUND 5 MPH EARLY IN THE  
EVENING...BECOMING LIGHT.  
CWR.................0 PERCENT.  
CHANCE OF PCPN......0 PERCENT.  
MIXING HEIGHT.......4600-5300 FT AGL...DECREASING TO 0-300 FT AGL.  
TRANSPORT WINDS.....SOUTHWEST 7 TO 15 MPH...DECREASING TO 3 TO 5  
MPH IN THE LATE EVENING AND OVERNIGHT.  
LVORI...............5.  
 
TIME (CDT) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM  
SKY (%).........MCR MCR CLR CLR CLR CLR CLR CLR CLR CLR CLR MCR  
WEATHER COV.....  
WEATHER TYPE....  
TEMP............83 80 76 72 68 66 64 63 62 61 60 59  
RH..............43 49 56 64 73 78 84 87 90 90 93 96  
20 FT WIND DIR..240 240 240 240 240 250 250 250 260 270 270 270  
20 FT WIND SPD..5 3 3 3 3 3 3 3 3 2 2 2  
20 FT WIND GUST.10 10 5 5 5 5 5 5 5 5 5  
MIX HGT (KFT)...5.3 4.6 3.2 1.6 0.3 0.1 0.1 0.3 0.2 0.2 0.2 0.1  
TRANSP WIND DIR.250 250 240 230 230 230 230 230 230 220 220 220  
TRANSP WIND SPD.15 14 10 7 3 3 3 5 5 3 3 3  
DISPERSION IDX..91 75 41 14 1 1 2 2 2 2 2 2  
LVORI...........1 1 1 1 4 4 4 7 7 7 8 8  
CWR.............0 0 0 0 0 0 0 0 0 0 0 0  
CHC OF PCPN (%).0 0 0 0 0 0 0 0 0 0 0 0  
   
WEDNESDAY
 
 
SKY/WEATHER.........SUNNY (10-20 PERCENT).  
MAX TEMPERATURE.....AROUND 86-88.  
MIN HUMIDITY........35-40 PERCENT.  
WIND (20 FT)........LIGHT WINDS...BECOMING SOUTHWEST 5 TO 7 MPH IN  
THE LATE MORNING AND AFTERNOON.  
CWR.................0 PERCENT.  
CHANCE OF PCPN......0 PERCENT.  
MIXING HEIGHT.......0-1400 FT AGL...INCREASING TO 2900-4700 FT AGL  
IN THE LATE MORNING AND AFTERNOON.  
TRANSPORT WINDS.....WEST 2 TO 9 MPH...BECOMING SOUTHWEST 9 TO 12  
MPH IN THE LATE MORNING AND AFTERNOON.  
LVORI...............5.  
 
TIME (CDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM  
SKY (%).........MCR MCR MCR MCR MCR MCR MCR MCR MCR MCR MCR MCR  
WEATHER COV.....  
WEATHER TYPE....  
TEMP............59 61 66 72 78 82 84 86 87 88 88 87  
RH..............100 93 81 66 54 47 43 39 36 35 35 36  
20 FT WIND DIR..250 240 250 260 270 260 250 250 240 240 230 230  
20 FT WIND SPD..2 2 3 3 5 5 6 6 7 7 7 6  
20 FT WIND GUST. 5 5 5 10 10 10 10 10 10 10 10  
MIX HGT (KFT)...0.1 0.2 1.4 2.9 4.2 4.5 4.5 4.3 4.5 4.7 4.7 4.7  
TRANSP WIND DIR.220 230 240 270 280 270 260 250 240 230 230 220  
TRANSP WIND SPD.2 3 6 9 12 12 10 9 9 9 10 12  
DISPERSION IDX..1 2 3 4 5 61 54 47 49 50 57 64  
LVORI...........8 5 5 5 1 1 1 1 1 1 1 1  
CWR.............0 0 0 0 0 0 0 0 0 0 0 0  
CHC OF PCPN (%).0 0 0 0 0 0 0 0 0 0 0 0  
 

 
FORECASTER...WEBER  
REQUESTED BY...CLARK  
TYPE OF REQUEST...PRESCRIBED  
.TAG 1708235.1/HUN  
.EMAIL KERRYCLARK@FS.FED.US  
 
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